This invention relates to a cooling device, especially to a centrifugal cooling tower designed for increased cooling efficiency, decreased loss of circulating water and a reduced tower size.
Generally, according to principles of cooling, cooling towers are used to absorb heat from water and to expose as much water surface area as possible to thereby accomplish the purpose of cooling. In conventional cooling towers, the heated water is permitted to flow out of the pipe inside the tower housing and there it drops through the cooled corrugated plates. Air is sucked in through an inlet and next passed out from the outlet at the top by the action of a motor-driven fan. After cooling the circulating air (absorbing heat from the air), heated water falls into a water tank below and in the process heat is released through tthe outlet at the top so that the water is cooled to a certain extent. During the process, although there is an exchange of heat, because the time of contact between the heated water and the air is rather short, the temperature of water still remains high and the cooling efficiency is very much limited. In use, therefore, the process is not as practical as it might be. This drawback is even more outstanding in the case of large-sized cooling systems.
It is therefore a purpose of the invention to make innovations upon the conventional cooling tower designs. In a large-sized cooling tower such as the one disclosed in U.S. Pat. No. 4,687,603, a fixed rotatable motor has to be supported on a plurality of beam structures. Because the tower has a large breadth and the supporting beams must exceed in length, it has made the supporting location less stable. Next, a deflection screen is provided on the outer circumference of the perforated cylinder where low and high temperature water on passing into the cylinder is slung out to hit against the net and forms into fine droplets. A fan is used to draw in the outside air through the louver slats provided for exchanging heat with water droplets in the compartment inside the tower. Cooling is accomplished when finally the high temperature air passes out through the opening at the top of the tower, whereas the low temperature water drops into a collecting tank. However, in use, the conventional cooling tower presents a number of design drawbacks, particularly, owing to a limitation in the arrangement of the lower and also the narrow opening at the top, the amount of circulating air is limited. Furthermore, when the heated water droplets (which are carried along by the high temperature air resulting from the heat exchange) pass out from the opening at the top, then there is a considerable loss of water from the circulation for cooling. It was therefore be necessary for water to be added in frequently through a ball float type water valve.
In view of the above-mentioned disadvantages, according to the invention an improved centrifugal cooling system has been devised which is capable of increasing the cooling efficiency, minimizing loss of circulating water and reducing the overall size of water towers.
Accordingly, the main object of the invention is to provide a large-sized cooling tower having the body frame thereof defined by a plurality of long slits. There is disposed near the upper end of the tower a bar screen structure for collection of water.
Fixed beams and a motor are mounted by a fixed post in the center portion of the housing. The fixed supports are attached respectively by a deflection screen member and a perforated drum of the double-function rotating cylinder supported in position by a shaft. A perforated drum is provided near to the upper portion with a spiral blade fan firmly fixed in position and the upper edge formed by the upper portion of this perforated drum is capable of engaging with a ring portion of the housing. In accordance with the arrangement of the invention, a large amount of outside air can be drawn in to promote better heat exchange with fine droplets of water. Additionally, the upwardly floating water vapor, on coming into contact with the bar screen structure, condenses to form drops of water, which fall down into a storage tank to be recirculated.